Sighting device



Mwah E@ G. L. EsToPPEY m-M3 SIGHTING DEVICE Original Filed Dec. 24, 1934 5 Sheets-Sheet l Zmventor (Ittorneg I March 19, 1940. Y

G. L. EsToPPEY 2,194,141

SIGHTING DEVICE Original Filed Dec. 24, 1934 5 Sheets-Sheet 2 rg @l Snoentor Gttotneg March 19, 1940. s. L. EsToPPEY 2,194,141

SIGHTING DEVICE ginal Filed Dec. 24 1934 5 Sheets-Sheet 3 f :inventor W attorney March .19, 1940. ESTQPPEY 2,194,141

SIGHTING DEVICE Original Filed Dec. 24, 1934 5 Sheets-SheetV 4 Alwenfor:

(Ittorneg Mwah H9, 1940. G, L, ESTOPPEY 2,194,141

SIGHTING DEvIcE original Filed Dec. 24, 1934 5 sheets-sneet's :inventor Gttorneg Patented if' 19,1940

STATES PATENT Application 11 Claims.

This invention relates to sighting devices such as are used on aircraft or other moving carriers and adapted to follow the movements of an objective to determine the proper time for bomb release in order that the bomb may strike the ob-v jective. y

One object oi the invention is the .provision of a sighting devi of, this character having an optical'system for following the movements of the objective, a movable reticle being provided for the optical system and provided with stabilizing means such asa gyroscope or the like for automatically controlling the reticle with reference to the bomb sight body. I

Another object of the invention is the provision of a bomb sight for'aircraft having means for determining the proper time for bomb release and having a reticlre which is effective on the eye of the bomber as lines of light' in the path of vision u of an optical system.

iinother object of the invention is the provision of a bomb sight or the like having an optical system provided with a 'transparent plate on which an image of the reticle is projected, the plate being movable about a transverse axis for relative displacement oi the reticlel image in the line of vision in accordance with the angle of approach or drift angie. a,

Another object of the invention is the provision 1, of a sighting device of the character mentioned having indicating means which give an indication as to the amount oi time remaining before the proper time oi bomb release.

Still another object of the invention is the provision of a bomb sight having an optical system in whichthe reticle is visible to the eye or' the bomber as lines of light, with means for controlling the intensity of the light lines to adapt the reticle illumination for either day or night time bombing.

December 24, 1934, Serial No. 758,919

Renewed July 11, 1939 the propel time 0f proper time for releasing ar bomb or projectil w" from an aircraft, but it is to be understood tha the invention is` susceptible of other uses where there isa relative movement between an objective\ and the sight and the two are at dierent elevations. The sight, as shown, embodies a. body it l5 which may be mounted in a suitable location on an aircraft or the like for horizontal swinging movement about an upright axis ii in order that thesight body may be turned or swung to main--1 tain the objective in the line of vision in case there is relative angular movement of the objeotive with reference to the sight, yor if a cross 'wind should be prevailing. Thus the sight body itfmay be rotatably mounted by means of the ange t supported in a suitable fixed bearing member 2i. in. its normal position, in the absence of any cross wind, the direction of the ground speed course is forward toward the target, in the dhecticn ofthe arrow a shown in mfg. 2. With a cross wind prevailing, or with an objective moving at an angle to the direction of approach, the air direction of movement of the aircraft, and of the bomb sight is indicated by arrow b, the sight body having been swung on the axis i i to maintain the ground course in line with the arrow a.

The bomb sight is provided with an optical system adapted to be trained on the objective so as to follow the 'apparent movements of the objective. This optical system, as shown, comprises a sight tube i3 suitably fixed in the body it and having. a system of lenses M, an eye pi i5, and a movable member or prism it whicht -rotatably mounted for` movement on a horizontal axis il, see Fig. 3, in order that the forwardly and downwardly directed line of sight to the objective may be varied as the aircraft travels in the general direction of the objective while the latter is maintained inview.

The tilting or rotational movements of the prism it are eected by a parallel link system into;

cluding links It connected to a double armed lever 2t xed to a gear segment'ti, and also pivotally connected to a double armed lever 22 towhich the prism it is secured. Rrational movements oi the segment 2i are eect d by a pinion 2t opf erated by segment 24 which is pivotally mounted on an axis 25 and which is fixed to a synchronizing link 26 .extending downwardly and forwardly. Ihe lower end of the link 26 is slotted as indicated at 21, or otherwise slidably related to a pin 28 of a synchronizing slide 29, thelatter being in' threaded engagement with a rotatable main screw 30. The speed of the screw 30 is so,

- justing screw 31 to bring the friction wheel 34 creased speeds.

closer to or further from the center of rotation 'of the friction disk 33 thus changing the speed of rotation of the shaft. 35, the latter being connected to a gear 38 provided in a gear train which differentially connects the shaft 35 to the main shaft 30 so that the speed of'the shaft 30 is proportional to the speed of the shaft 35, the differential connection being such, however,'that additional movements may be imparted to the shaft 36 by gear system 39 controlled from shafts 40 and 4| and underthe operatorscontrol by rea- This construction is similarI to the arrangement set forth in my prior application for United States Letters Patent Serial 'No. 479,950, filed September 5, 1930., Patent Number 2,118,041, May 24, 1938, the construction providing lfor a control of the speed of the sighting member by power means under the control of the operator' so as to maintain the objective in the line of vision.

Speed adjusting screw 31 is turned by the oper.- ator who effects the required turning of knob 42 to position the bracket 36 for increased or de 'As the bracket'36'moves along screw 31 an adjustable range link 44 is moved angularly Aabout its pivotal connection 45. the lower end of the link 44' being slotted and en'- gaging a pin 46 on the bracket 36. 'This adjusts the position of the release, control slide 41which is slidably mounted ona rod 48 and which is adapted to cooperate with thc synchronizing slide 29 for determining the proper time for bomb release. The point of pivotal connection of the link 44 is vertically-adjustable under theH control of a screw 5U which is in threaded engagement with the nut 5I. The screw 50 may be rotated by a gear train including gears 52 and which-are operated by an adjusting knob 66.

By turning the'knob 56 an altitude trail correction is made in the setting of .thenut 5I, and atthe same time the altitude trail cam 51 is positioned. A drum 54, having a series of altitude' scales .each for' a different terminal velocity is also setas the gear 52 is turned. Surrounding.. the drum 54 is a shell 54' having index openingseach cooperating with one of the altitude scales on the drum 54. The shell 54' is turned in ac-g the bomb sight body lo.

son of the adjustable manually controlled knob adjustable slide 59 which is slidably supported for movement in the direction of the arrow a on supporting bars 60 which aresuitably fixed on The longitudinal or forward adjustment of the slide 59 moves the pivot axis 25 in a forward direction to eiect the necessary longitudinal component'of the trail correction to control several factors. As shown in Fig. 2, longitudinal adjustment of the 'slide 59 is effected by the altitude trail correction cam 51 which, when rotated, moves an arm 62 :transversely and effects a longitudinal component correction on the slide 59 through. the link 63 which is pivotally connected at $4 to the bracket 65 projecting rearwardly from the slide 5 9. Link 63 is also interlinked with 'an adjusting link 66 which is movable laterally under the control of an arm 61 pivoted at 6.8 and movable'under .the control of a cam 63 which is fixed to the support on which the bomb sight body I0 is pivoted so that as the bomb sight body is turned about its vertical axis the arm 61 is adjusted automatically to effect a longitudinal component of the trail correction in accordance with the drift angle or angle of approach or both. Another longitudinal component'l of the trail correction is effected by a'ma'nually controlled knob 10 which operates an air temperature compensating shaft 1l having a control link 1 2 whichis'interlinked withthe adjusting arm 66 and also pivotally connected at 13 tov an adjustable member 14. 'Ihe member 14 itself may be moved forwardly under thecontrol of the manually adjustable knob 15 which is adjusted by the 'bomber in accordancewith air speed and terminal velocity of -the bomb.

Supported on the slide 56 is a laterally adjustable slide 11 having a rearwardly extending arm 18 which is connected as will be more fully set forth, to the laterally adjustable reticle plate of the optical system. Lateral adjusting movements 'of the slide '11' are impartedautomatically.A

' accordance with the drift angle o`r angle of approach 'or both. The cam 69 has' a straight slot which controls a pin I I fixed to.an arm 62 projecting from the slide 11.

The aircraft cannotalways maintain a persight lwould not have to be stabilized by a large,

fectly horizontal attitude -durlng the'bombing operation. and in order that the .entire bomb heavy and expensive gyroscop'e or stabilizing apparatus. the opticalY system comprises a stabilized reticlc. the stabilized part being ajsmall and light. member-.as compared with-the entire bomb sight. stabilizing means may be provided, and the sighti ing'tube I3 may be fixed on the bomb sight and the latter in turn mounted on a vertical axiswhich is-fixed on theaircraft. Asshown more 'fully in Fig. 5. a reference or reticle member 8.4

by the prism a. and passes through the glass. plate 86 onto a. parallel glass plate l1 provided -in the eld of vision of the tube I3. The refer- 'I-hus a very small gyroscope or other 35..4 'Ihe light passing .through the' ence member 64 is automatically stabilized vby means of a gyroscope' or the like indicated at 88 and mounted on a suitable supporting'bracket .Il

for movement either in a lforward or lateral dlrection so that the reference member 04 will be automatically maintained in a predetermined position with regard to the ground in spite of any tilting movements of the bomb sight body. The reticle itself is apparent to the observer or bomber as he looks through the optical system as crossed lines of light apparent on the parallel plate 81 which is normally inclined at an angle of 4:5 degrees and which is transparent so that the objective willbe apparent through it.

The amount of light produced by the lamp 85, as shown in Fig. 1, is controlled manually by means of an adjusting knob 9| which controls a resistance 92 in series with the battery 93' or other source of energizing power, the power being connected to the ,lamp 85 when the main switch 94 is closed.- The amount of light coming from the lamp 05 is regulated so as to give reticle lines of light, apparent to the bomber, of sucient brightness for use in daytime bombing, or of sumciently-low intensity for use in night time bomb'ng. Thus the brightness of the reticle will be cient for ready observation l but not so excessive as to prevent accurate observation of the objective itself.

The reference member 04 as shown in Fig. 5 is provided at one side of the telescope, although for diagrammatic illustration `it has been shown l) in Fig. 1 to the rear of the telescope. The reticle lines thrown on the parallel plate 81 are automatically stabilized, as previously described, and. means are also provided for moving the image of the reticle laterally with respect to the line l' of vision through the sighting tube I3, thelateral adjustment of the reticle being eected automatically in accordance with the amount Iof angular movement of the bomb sight body on its vertical axis from a normal position. As

c the bomb sight body is adjusted on its vertical axis, as will be apparent from Fig. 2, the arm 18 on the laterally adjustable slide 'l1 is moved laterally,l and. its lateral movements are im- 1 parted by means of a pivoted arm 98', see Fig.

5 5, to an arm 91 which is xed to the parallel plate 01, the latter being rotatably mounted on a transverse horizontal axis so that the angle of tilt of the parallel plate maybe adjusted.`

Adjusting movements of the parallel plate 81 on its horizontal axis have the effect of moving -the reticle image laterally so as to give the proper inclination of the line 'of sight to the objective to compensate for cross winds or for relative-` angular movement of the objective with reference to the ground speed course.

At the exact time of bomb release, a contact is automatically closed by the synchronizing slide 29, which is illustrated in Fig. 1 together with a portion of the screw 30 with which it is 0 vin threaded engagement. The slide 29 carries a contact |00 which is connected to the bomb'release magnet when the safety bomb release switch. |0I is closed. The connection is from the upper1 s ide of the release magnet |04 through '.5 the closed switch |0| and directly to the contact |00, the other side of the magnet |04 being con-` nected tothe negative side of the batteries 93 as indicated in Fig. 1. When the contact |00'engages a second contact v|02 provided on the slide,

41 of rod 48,' contact is made through the line |03 to one side of the battery 93, that is the, positive side, as indicated in Fig. 1, thus ener- 1 gizing the release winding |04 which eii'ects the release of the bomb |05. When the contacts |00 and |02 engage and eifect the release of the bomb, the switches 0l' and Illia having been closed/ a circuit is energized through a signal lamly |01 which is illuminated. One side of the signal lamp |01 is connected directly to thel contact |00 so that when contacts |00 and |02-5 engage that'side is connected to the positive side of the battery through wire |03. The other side of the lamp |01'is connected through the closed, switch 0l directly to thenegative side of the` battery. This lamp |01 as shown in Fig. 5 10 throws light on the transparent plate 86 which reects the light onto the parallel plate 81, il-v luminating an area on the plate, and thus giving an indication to the bomber that thebomb is gone and that he need no longer continue to follow the movements of the objective on the optical system. As a further aid to the bomber,

and to keep the vbomber fully infomed as to I how much time remains befor'e the bomb is to be `dropped, an indicatorneedle |09 of a volt 20 meter or milli-ammeter ||0 is visible to the bomber, the end of the needle swinging in an arc at one side of the center line of sight. The instrument ||0 has one end connected to a movable contact provided onl slide 20. The other end of the instrument is connected to the slide 41. Well before contacts |00 and |02 e'ngage, and before contact I|| engages with the slide 41, no indication of the needle |09 is given. the needle thus being in its normal position. 80 However, as the time for release of the bomb approaches, and before the time for -release is at hand, the contact engages and moves along a resistance or potentiometer ||2 which is connected at one end to the line I03-and thus to the positive side of the battery. Thev other side 'of the battery is connected through the closed switch 94 to the other end of they resistance ||2and to one side of the instrument H0. The voltage Aapplied to the instrument ||0 0 is thus dependent on the position of the contact upon the potentiometer H2. As soon as the contact Ill engages the-right-hand end of the resistance H2. see Fig. 1, the needle swings over to its full extent and thus indicates to the 5 bomber that the time for bomb lrelease is getting rather close. As the contact ||I moves to the left along the resistance V| I2 the needle gradually returns to its normal position, and its amount of deiiection from its normal position. 50.

forms an indication as-to the amount of time still remaining before the proper timeeof bomb release. 'Ihe bomber is thus enabled to accurately control the instrument to maintain the' obv-jective more accurately in the line of. vision 55;

during the last portion of the 4synchronizing operation. As above mentioned, when the time for bomb release is at hand, the bomb is automatically released and an VAarea on the parallel plate 81 is llllllnillitted.v 'telling the bomber that the 60- bomb is gone. However, it will be noted particularly that this illumination oi' an area on the plate 81 does not take place before the bomb goes. and thus does not disturb the bombers synchronizing operations.

While the formof apparatus herein described constitutesa preferred embodimentof the inventlon, it is` to beunderstood that the invention is not limited to this precise form of apparatus.

and, .that changes may be made therein without Y7o `departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In -a sighting device of the character described, an'optical system mounted thereon for 75 sighting a targetV and having a movable element for keeping the target in the line of vision, a reticle for said optical system, means for stabilizing said reticle with reference to the ground as the sighting device is tilted, means for rotatably supporting said sighting device lon a vertical axis, and a second movable element having transparent property and reecting property and mounted in the optical system between -the rst movable elementand the eye location of the observer and reflecting the reticle to the eye of the observer, said second element being movable independently of the rst' element to produce an apparent lateral motion of the reticle with reference to' the ground speed course to incline the line 'of sight in accordance with the rotational movements of the sighting device about said vertical axis to compensate for drift angle and angle of approach.

2. In an aircraft bomb sighting device, a body mounted for turning movement on a vertical axis fixed onthe aircraft, a sighting tube vertically positioned on said body and having a. movable portion rotatable about a horizontal axis ixed'onsaid body for keeping the target in the line of vision, a reticle for said sighting tube,'gyroscopic means for stabilizing said reticle in said body with reference to the ground as the sighting device is tilted, and additional means provided between said movable portion and the eye 0f the observer for automatically producing an apparent motion of the reticle laterally in the sighting tube and With Vreference to the ground speed course to incline the line of sight in accordance with. the Aangle of turn of said body about said vertical axis to compensate for drift angle and angle of approach.

3. In a sighting device of the character described, an opaque reference member having crossing transparent reticle lines and movably supported, for movement about a plurality oi.

horizontal axes on the sighting device, stabilizing means for maintaining said member in predetermined position with reference to the ground as the sighting device is tilted, a sighting tube mounted on said sighting device having a movable sighting memberfor following an objective and having a transparent plate in the path of vision of said sighting tube, means supporting.

said sighting device for rotational movement about a vertical axis, means for rotatably adjusting saidA transparent plate about a horizon-' tal axis, and a. light source xed with respect to said sighting tube and cooperating with said reference' member for projecting the reticle lines as crossing lines iat-light on said plate.

4. In a sighting device ofthe character described, a body mounted forturning movement on a Xed vertical axis, an optical sighting system comprisinga. sighting tube vertically positioned on said body and having a movable portion rotatably mounted on a horizontal axis for keeping the targetin the line of vision, a transparent plate, means pivotally supporting' said plate for movement about a horizontal axis, an opaque reference member having transparent reticle lines, a light source cooperatively associated with said reference member for project-l ing the reticle lines as lines of light onto said transparent plate in the path'of vision o f saidoptical system, means for adjusting said plate about its horizontal axis -for trail correction, and means for stabilizing said reference member in a v predetermined normal position. I 5 In -a sighting device of the character described, a reference member having reticle lines and movably supported on the sighting device,

stabilizing means formaintaining saidmember --i'na predetermined position with reference to the ground as the sighting device is tilted, an optical system mounted on said sighting device and having a transparent inclined plate in the I path of vision of said optical system, said optical systemv having a' movable portion rotatably mounted on a horizontal axis for keeping the target in the line of vision, a light source cooperatively associated With said reference memtatably supporting said sighting device for movel ment about a vertical axis, and means for moving said plate on its axis in ,accordance with rotational movements of the sighting device about said vertical aids.

' 6. In an aircraft bomb sighting device', a body mounted for turning movement on a fixed vertical axis, an optical sighting system comprising a sighting tube lpositioned on said-body and having a movable portion rotatably mounted on a. horizontal axis for keeping the target in the line' of vision, an opaque reference member having transparent reticle lines, means for stabilizing said reference member, a transparent plate provided in the iield of vision of the optical system, a light source cooperatively associated with said reference member for projecting the reticle lines as lines of light on said plate and in the path of vision of said optical system, and means for moving said plate on a horizontal laterally ex- .tending axis in accordance with. drift angle and angle of approach.

7. In an aircraft bomb sighting device, a body, an optical system positioned on said body and having a vmovable portion rotatably mounted for release at various altitudes, means for moving.

the pointer to some displaced positionat some predetermined time in the bombing operation 'before the proper time for bomb 'release-arid means for automatically movingl said pointer gradually to said predetermined position in accordance with the time interval existent before the proper time for bomb release including means for determining its rate of movement in accordance with altitude of the aircraft.

8. In an aircraft bomb sighting device, a body mounted for turning movements on xed vertical axis, an optical system comprising a sighting tube positioned on said body and having a movable portion rotatably mounted on a horizontal axis for keeping the target in the line of vision, a reticle for said optical system, means for stabilizing said reticle with reference 'to the body, an instrument pointer movable in the line of vision of the optical system to the same pre- "determined position to indicate the proper, time for bomb release at various altitudes, means for moving the pointer to some displaced position at some predetermined time in the bombing operation before the proper time for bomb release, andA means for automatically moving said pointer gradually to said predetermined position in ac-- cordance with ',he'time'interval existent before means for determining its rate oi movement in accordance with altitude of the aircraft.

9. In a sighting device of the character described, a body mounted for turning movement on a iixed Vertical axis, an optical sighting system comprising a sighting member positioned on said body and having a movable portion rotatably mounted for keeping the target in the line of vision, bomb releasing means, an opaque reference member having transparent reticle lines, a transparent plate in the line oi vision, a iight source fared on said body ior illuminating said reticle lines and projecting the same as visible lines 03E iight on said transparentpiate, means` for electrically controlling the pov/er supplied to the lignt source for controlling the intensity oi illumination of said light source, an additional iight source :for producing a bright area oi illamination on said transparent plate in the path of vision of the optical system, and means automaticailyoperable by said bomb releasing means for' automatically energizing the additional light source when the lcomlo is released.

i0. In a sighting device oi the character described, an optical system mounted thereon for sighting a target and haring a movable element for keeping the target in the line of vision, a reticle for said optical system, gyroscopic means `or stabilizing said reticle with reference to the ground as the sighting devi-ce is tiltr` l, meansior rotatably supporting said sighting device on a vertical axis, and a second movable element in- -terposed in the line of sight in series with the rst element and movable independently or the rst element in accordance with the rotatable movements of the sighting device on said vertical axis to produce an apparent lateral motion of the reticle with reference to the ground speed course.

ll. In an aircraft bomb sighting device, a body mounted or turning movement on a vertical airis fixed on the aircraft, an optical system arranged in said body for sighting a target and having a movable element :for keeping tire target in the line oi" vision, a reticle ior said optical system, gyroscopic means for stabilizing said reticie with reference to the ground as the ioody is tilted by tilting movement oi 'the aircraft, and means interposed in said optical system between the movable element and the eye location of the observer and movable independently of the element in a lateral direction to incline the line of sight by producing an apparent lateral motion oi the reticle with reierence to the ground speed course, and mechanism `vfor operating said last means in accordance with the amount of rotation of the body on. its vertical Sii 

